1
- (especially of change or action) relating to or affecting the fundamental nature of something: far-reaching or thorough（尤指变化或行动）根本的; 意义深远的, 彻底的：
a radical overhaul of the existing regulatory framework.
对现有管理体制的彻底检查。
1.1
- forming an inherent or fundamental part of the nature of someone or something（人, 物）原本的, 固有的, 与生俱来的：
the assumption of radical differences between the mental attributes of literate and non-literate peoples.
就有文字民族与无文字民族之间智力特征固有差异的假设。
1.2
- (of surgery or medical treatment) thorough and intended to be completely curative（外科, 医疗）根治的, 根除的。
1.3
- characterized by departure from tradition: innovative or progressive反传统的; 创新的, 革新的; 进步的：
the city is known for its radical approach to transport policy.
该市以交通政策方面的革新而著称。
2
- advocating thorough or complete political or social reform: representing or supporting an extreme or progressive section of a political party过激的; 激进的, 激进派的：
a radical American activist.
美国激进主义分子。
2.1
- (of a measure or policy) following or based on such principles（措施, 政策）彻底革新的; 激进性的。
2.2
- Brit. historical belonging to an extreme section of the Liberal party during the 19th century〈英, 史〉（19世纪）自由党激进派的。
3
- of or relating to the root of something, in particular（与）根（有关）的, 尤指：
3.1
- Mathematics of the root of a number or quantity【数】根式的; 根号的; 根基的。
3.2
- denoting or relating to the roots of a word词根的。
3.3
- Music belonging to the root of a chord【乐】根音。
3.4
- Botany of, or springing direct from, the root or stem base of a plant【植】根生的。
4
- usu. as exclamation informal, chiefly US very good: excellent〈非正式, 主美〉顶刮刮的：
Okay, then. Seven o'clock. Radical!
好吧。七点钟。太棒了！
1
- a person who advocates thorough or complete political or social reform: a member of a political party or part of a party pursuing such aims过激主义者; 激进主义者; 激进党派成员。
2
- Chemistry a group of atoms behaving as a unit in a number of compounds【化】基, 根, 原子团。参见FREE RADICAL.
- ORIGIN: early 19th cent.: from French.
3
- the root or base form of a word词根。
3.1
- any of the basic set of approximately 214 Chinese characters constituting semantically or functionally significant elements in the composition of other characters and used as a means of classifying characters in dictionaries（汉字）偏旁, 部首。
4
- Mathematics a quantity forming or expressed as the root of another【数】根式; 根基。
4.1
- a radical sign根号。
派生词
radicalism
noun （限名词义项2）radically
adverb截然不同的方法
radicalness
noun词源
late Middle English (in the senses forming the root and inherent)： from late Latin radicalis, from Latin radix, radic- 'root'.